When I read Revelation I'm always puzzled about the sea giving up the dead that were in it and it is counted as a separate event than death and hell delivering up the dead which were in them. It almost seems as if a soul or a spirit cannot pass through water.
Revelation 20 King James Version
12 And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.
13 And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works.
Looking further we read that when an evil spirit is gone out of a person then they walk through dry places and in both instances below it makes a point of mentioning dry places as opposed to just walking around.
Matthew 12 King James Version
43 When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest, and findeth none.
44 Then he saith, I will return into my house from whence I came out; and when he is come, he findeth it empty, swept, and garnished.
45 Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
Luke 11 King James Version
24 When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest; and finding none, he saith, I will return unto my house whence I came out.
25 And when he cometh, he findeth it swept and garnished.
26 Then goeth he, and taketh to him seven other spirits more wicked than himself; and they enter in, and dwell there: and the last state of that man is worse than the first.
In the account below, Jesus gives instruction to the evil spirit that it is not permitted to enter in to the boy any more which is contrary to what they normally would do. Possibly because of the boy's age because he had not yet reached the age of accountability.
Mark 9 King James Version
20 And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming.
21 And he asked his father, How long is it ago since this came unto him? And he said, Of a child.
22 And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us.
23 Jesus said unto him, If thou canst believe, all things are possible to him that believeth.
24 And straightway the father of the child cried out, and said with tears, Lord, I believe; help thou mine unbelief.
25 When Jesus saw that the people came running together, he rebuked the foul spirit, saying unto him, Thou dumb and deaf spirit, I charge thee, come out of him, and enter no more into him.
In the accounts below though, Jesus didn't command the evil spirits that they were not to enter in to those set free again but they were allowed to enter in to the swine. I assume though that when the swine would have died by slaughter or other natural means then the evil spirits would be able to leave the swine and enter in to a person which is something I'm sure they would like to do.
Matthew 8 King James Version
28 And when he was come to the other side into the country of the Gergesenes, there met him two possessed with devils, coming out of the tombs, exceeding fierce, so that no man might pass by that way.
29 And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time?
30 And there was a good way off from them an herd of many swine feeding.
31 So the devils besought him, saying, If thou cast us out, suffer us to go away into the herd of swine.
32 And he said unto them, Go. And when they were come out, they went into the herd of swine: and, behold, the whole herd of swine ran violently down a steep place into the sea, and perished in the waters.
Mark 5 King James Version
2 And when he was come out of the ship, immediately there met him out of the tombs a man with an unclean spirit,
3 Who had his dwelling among the tombs; and no man could bind him, no, not with chains:
4 Because that he had been often bound with fetters and chains, and the chains had been plucked asunder by him, and the fetters broken in pieces: neither could any man tame him.
5 And always, night and day, he was in the mountains, and in the tombs, crying, and cutting himself with stones.
6 But when he saw Jesus afar off, he ran and worshipped him,
7 And cried with a loud voice, and said, What have I to do with thee, Jesus, thou Son of the most high God? I adjure thee by God, that thou torment me not.
8 For he said unto him, Come out of the man, thou unclean spirit.
9 And he asked him, What is thy name? And he answered, saying, My name is Legion: for we are many.
10 And he besought him much that he would not send them away out of the country.
11 Now there was there nigh unto the mountains a great herd of swine feeding.
12 And all the devils besought him, saying, Send us into the swine, that we may enter into them.
13 And forthwith Jesus gave them leave. And the unclean spirits went out, and entered into the swine: and the herd ran violently down a steep place into the sea, (they were about two thousand;) and were choked in the sea.
But in this account below the evil spirits were concerned about being sent in to the deep. I wonder if the reason for that is because once they are in the water there is no way for them to ever get the freedom they need in order to inhabit another person. Unbeknown to them, they were heading for the deep whether they liked it or not.
Luke 8 King James Version
26 And they arrived at the country of the Gadarenes, which is over against Galilee.
27 And when he went forth to land, there met him out of the city a certain man, which had devils long time, and ware no clothes, neither abode in any house, but in the tombs.
28 When he saw Jesus, he cried out, and fell down before him, and with a loud voice said, What have I to do with thee, Jesus, thou Son of God most high? I beseech thee, torment me not.
29 (For he had commanded the unclean spirit to come out of the man. For oftentimes it had caught him: and he was kept bound with chains and in fetters; and he brake the bands, and was driven of the devil into the wilderness.)
30 And Jesus asked him, saying, What is thy name? And he said, Legion: because many devils were entered into him.
31 And they besought him that he would not command them to go out into the deep.
32 And there was there an herd of many swine feeding on the mountain: and they besought him that he would suffer them to enter into them. And he suffered them.
33 Then went the devils out of the man, and entered into the swine: and the herd ran violently down a steep place into the lake, and were choked.
So not just evil spirits but also maybe the souls of men that if they die in the water then they remain where they are until they are recovered from the sea for judgement. I don't think it's a major doctrine or anything but I do think it's interesting.